Tuesday, June 26, 2007

The proliferation of drifting Antarctic icebergs caused by rising temperatures is creating a vast new ecosystem of plankton, krill and seabirds that may have the power to absorb some of the carbon dioxide that is driving global warming, scientists reported Thursday.

The researchers, led by oceanographer Kenneth Smith Jr. of the Monterey Bay Aquarium Research Institute in Moss Landing (Monterey County), found that these iceberg-associated communities may cover a significant portion of Antarctic seas.

The ecosystems use photosynthesis to take carbon from the atmosphere and convert it into plant life and other forms of organic carbon that can be held in the ocean. "I think it can be a substantial contribution" to reducing carbon dioxide levels, Smith said. "These things have been ignored forever."

As glaciers move across Antarctica, they accumulate nutrient-rich dirt and dust. When rising temperatures prompt the glaciers to break up, the resulting icebergs carry that material out to sea.

The researchers, who published their findings in the online version of the journal Science, analyzed two icebergs in the Weddell Sea, at the southernmost part of the Atlantic Ocean.

They found that soil and other organic matter escaping from the icebergs provided nutrients and support for plankton and algae. Krill then fed on the plankton.

This blog is part of the ongoing work of the American River Parkway Preservation Society to provide public education and advocacy around public policy issues that may be related to the Parkway and the adjacent communities along the American River in Sacramento, California.